You are absolutely correct. My experience, which is by no means exhaustive, is that "symbol rate" vs "baud rate" vs "bit rate" and "protocol encoding" vs "data

You are absolutely correct. My experience, which is by no means exhaustive, is that "symbol rate" vs "baud rate" vs "bit rate" and "protocol encoding" vs "data bits" are topics that go deep but can quickly overwhelm someone thinking about this stuff for the first time (or at least nearly so). So to reassure you I was trying to be more "accessible" than "precise" in my writing here. And yes, I often miss the mark and go too far one way or the other. That said building large constellation QAM modulator/demodulators is a lot of fun I've discovered, but building real world modems that can deal with fading, reflections, and multipath takes away the fun pretty quickly :-).